Synaptosomal [125I]triiodothyronine after intravenous [125I]thyroxine.

1978 ◽  
Vol 235 (6) ◽  
pp. E638
Author(s):  
M B Dratman ◽  
F L Crutchfield
Keyword(s):  
Nervous System ◽  
Amino Acid ◽  
Male Rats ◽  
Time Interval ◽  
Nerve Terminals ◽  
Brain Uptake ◽  
Uptake Mechanism ◽  
Hormone Administration ◽  
Adrenergic Nervous System ◽  
Brain Cytosol

We administered [125I]thyroxine intravenously to adult male rats and measured uptake and subcellular distribution of the hormone and its metabolites in brain. Fractional brain uptake decreased after a large dose of iodothyronine, providing evidence for saturability of the uptake mechanism. Well-defined patterns of regional and subcellular labeling were noted within 1 h after [125I]thyroxine injection. Radioactivity in synaptosomes was always greater than in any other particle separated per gram of brain, increasing linearly relative to radioactivity in brain cytosol during the 1st h. Although [125I]triiodothyronine derived from [125I]thyroxine was not identified in serum at any time interval, it was measurable in synaptosomes within 20 min and in brain cytosol within 1 h after labeled hormone administration. Concentrations of the radioactive metabolite were twofold greater and ratios of [125I]triiodothyronine to [125I]thyroxine concentration were threefold greater in synaptosomes than in cytosol. Therefore, thyroxine may be converted to triiodothyronine within nerve terminals. Synaptosomal localization of iodothyronines and their metabolites may be relevant to the marked central and peripheral adrenergic nervous system effects of these aromatic amino acid hormones.

scholarly journals Cgrp Uptake into Perivascular Capsaicin-Sensitive Nerve Terminals

2001 ◽  
Vol 1 ◽  
pp. 3-3
Author(s):  
A. Sams-Nielsen ◽  
C. Orskov ◽  
I. Jansen-Olesen
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Amino Acid ◽  
Neuronal Uptake ◽  
Nerve Terminals ◽  
Amino Acid Neurotransmitters ◽  
The Central Nervous System

Specific mechanisms, providing reuptake of cathecholamine and amino acid neurotransmitters (e.g., serotonin and glutamate) into cells of the central nervous system are well known, whereas neuronal uptake of neuropeptides have not previously been reported.

General Anesthetics Do Not Affect Release of the Neuropeptide Cholecystokinin from Isolated Rat Cortical Nerve Terminals

2002 ◽  
Vol 97 (6) ◽  
pp. 1500-1506 ◽  
Author(s):  
Victor N. Pashkov ◽  
Robert I. Westphalen ◽  
Hugh C. Hemmings
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Amino Acid ◽  
Volatile Anesthetics ◽  
Nerve Terminals ◽  
General Anesthetics ◽  
Neuropeptide Release ◽  
The Central Nervous System ◽  
Isolated Rat

Background General anesthetics inhibit evoked release of classic neurotransmitters. However, their actions on neuropeptide release in the central nervous system have not been well characterized. Methods The effects of representative intravenous and volatile anesthetics were studied on the release of sulfated cholecystokinin 8 (CCK8s), a representative excitatory neuropeptide, from isolated rat cerebrocortical nerve terminals (synaptosomes). Basal, elevated KCl depolarization-evoked and veratridine-evoked release of CCK8s from synaptosomes purified from rat cerebral cortex was evaluated at 35 degrees C in the absence or presence of extracellular Ca2+. CCK8s released into the incubation medium was determined by enzyme-linked immunoassay after filtration. Results Elevation of extracellular KCl concentration (to 15-30 mM) or veratridine (10-20 microm) stimulated Ca2+ -dependent CCK8s release. Basal, elevated KCl- or veratridine-evoked CCK8s release was not affected significantly by propofol (12.5-50 microm), pentobarbital (50 and 100 microm), thiopental (20 microm), etomidate (20 microm), ketamine (20 microm), isoflurane (0.6-0.8 mM), or halothane (0.6-0.8 mMm). Conclusions Clinically relevant concentrations of several classes of general anesthetics did not affect basal, KCl-evoked, or veratridine-evoked CCK8s release from isolated rat cortical nerve terminals. This is in contrast to the demonstrable effects of certain general anesthetics on the release of amino acid and catecholamine transmitters. These transmitter-specific presynaptic effects of general anesthetics suggest that anesthetic-sensitive presynaptic targets are not common to all transmitter classes.

METABOLIC STUDIES WITH 131I-LABELED THYROXINE. II.

1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Pituitary Gland ◽  
Time Interval ◽  
Time Intervals ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
Tentative Explanation

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.

Vasopressin analogues with effect on central nervous system: Synthesis and biological properties

1983 ◽  
Vol 48 (10) ◽  
pp. 2862-2873 ◽  
Author(s):  
František Brtník ◽  
Ivan Krejčí ◽  
Běla Kupková ◽  
Pavel Hrbas ◽  
Jana Škopková ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Amino Acid ◽  
Passive Avoidance ◽  
Biological Properties ◽  
Passive Avoidance Test ◽  
System Synthesis ◽  
Avoidance Test ◽  
Vasopressin Analogues

Synthesis of four vasopressin analogues which do not contain the glycinamine residue in position 9 and have a basic non-coded amino acid in position 8 is described. All the analogues exhibit very low endocrine activities and are effective in the passive avoidance test.

scholarly journals Spinal mechanisms contributing to the development of pain hypersensitivity induced by sphingolipids in the rat

2021 ◽  
Author(s):  
Hong Wei ◽  
Zuyue Chen ◽  
Ari Koivisto ◽  
Antti Pertovaara
Keyword(s):  
Amino Acid ◽  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Gap Junction ◽  
Male Rats ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Mk 801 ◽  
Mechanical Hypersensitivity ◽  
Pain Hypersensitivity

Abstract Background Earlier studies show that endogenous sphingolipids can induce pain hypersensitivity, activation of spinal astrocytes, release of proinflammatory cytokines and activation of TRPM3 channel. Here we studied whether the development of pain hypersensitivity induced by sphingolipids in the spinal cord can be prevented by pharmacological inhibition of potential downstream mechanisms that we hypothesized to include TRPM3, σ1 and NMDA receptors, gap junctions and D-amino acid oxidase. Methods Experiments were performed in adult male rats with a chronic intrathecal catheter for spinal drug administrations. Mechanical nociception was assessed with monofilaments and heat nociception with radiant heat. N,N-dimethylsphingosine (DMS) was administered to induce pain hypersensitivity. Ononetin, isosakuranetin, naringenin (TRPM3 antagonists), BD-1047 (σ1 receptor antagonist), carbenoxolone (a gap junction decoupler), MK-801 (NMDA receptor antagonist) and AS-057278 (inhibitor of D-amino acid oxidase, DAAO) were used to prevent the DMS-induced hypersensitivity, and pregnenolone sulphate (TRPM3 agonist) to recapitulate hypersensitivity. Results DMS alone produced within 15 min a dose-related mechanical hypersensitivity that lasted at least 24 h, without effect on heat nociception. Preemptive treatments with ononetin, isosakuranetin, naringenin, BD-1047, carbenoxolone, MK-801 or AS-057278 attenuated the development of the DMS-induced hypersensitivity, but had no effects when administered alone. Pregnenolone sulphate (TRPM3 agonist) alone induced a dose-related mechanical hypersensitivity that was prevented by ononetin, isosakuranetin and naringenin. Conclusions Among spinal pronociceptive mechanisms activated by DMS are TRPM3, gap junction coupling, the σ1 and NMDA receptors, and DAAO.

scholarly journals Methionine sulphoxide as a source of sulphur-containing amino acids for the young rat

1977 ◽  
Vol 37 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Anne U. Gjøen ◽  
L. R. Njaa
Keyword(s):  
Amino Acid ◽  
Blood Plasma ◽  
Fish Meal ◽  
Soya Bean ◽  
Male Rats ◽  
Curvilinear Relationship ◽  
Casein Diet ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Effect On Growth

1. Young male rats were used in five experiments to study the utilization for growth of methionine sulphoxide, and the relationship between the sulphoxide content in the diet and the level of microbiologically determined methionine activity in blood or blood plasma. In one nitrogen-balance experiment methionine and methionine sulphoxide were compared as supplements to a casein diet and a fish-meal diet.2. Methionine sulphoxide was poorly utilized for growth when tested as the sole sulphur amino acid in an amino acid diet. Substitution of one-third of the sulphoxide with cystine improved utilization so that it approached that of methionine.3. Methionine alone and in combination with methionine sulphoxide were added to a soya-bean-meal diet. The sulphoxide showed no adverse effect on growth.4. Fish meal in which methionine had been oxidized to methionine sulphoxide was tested alone and in combinations with unoxidized fish meal. Only when the oxidized meal was given alone was there an appreciable effect on growth. The fish meals used were low in cystine.5. Whereas both methionine and methionine sulphoxide improved the N balance when a casein diet was given, there was no effect when a fish-meal diet was given.6. There was a linear relationship between methionine sulphoxide content in the amino acid diets and the methionine activity in the blood plasma. Methionine sulphoxide added to a soya-bean-meal diet or present in oxidized fish meal gave a curvilinear relationship, and the observed activities were lower than with the amino acid diets. Methionine activity in blood could not be used as an indicator of moderate amounts of methionine sulphoxide in protein-containing diets.

Evaluation of the Impact of Short Duration Music Listening on Autonomic State (Preprint)

2021 ◽  
Author(s):  
Garry Elvin ◽  
Paras Patel ◽  
Petia Sice ◽  
Chirine Riachy ◽  
Nigel Osborne ◽  
...  
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Short Duration ◽  
System Response ◽  
Time Interval ◽  
Music Listening ◽  
Autonomic Nervous ◽  
The Impact ◽  
Change In Mean

BACKGROUND Heart rate variability (HRV), or the variation in the time interval between consecutive heartbeats, is a proven measure for assessing changes in autonomic activity. An increase in variability suggests an upregulation of the parasympathetic nervous system (PNS). Music was shown to have an effect on the limbic system, respiratory rate, and blood pressure. However, there have been relatively few empirical investigations on the effect of music on HRV compared to mean heart rate (HR). Also, the majority of studies have been experimental rather than interventional, reporting significant changes in HRV as a function of musical characteristics, such as tempo, genre, and valence. OBJECTIVE The aim of this pilot study is to evaluate the impact of short duration music listening on the autonomic nervous system response of healthy adults. METHODS Six participants (three males and three females) were tested to investigate the effect of listening to music on HR and HRV. Electrocardiographic (ECG) data was recorded at a sampling rate of 1000 Hz using an eMotion Faros 360 device produced by Bittium Biosignals. The data was collected while the participants listened to four pre-selected songs in a random order separated by a relaxation period of 5 minutes. Data was then cleaned and processed through Kubious HRV 2.0 software. Statistical analysis using Wilcoxon signed rank test was carried out for the time and frequency domains. RESULTS For all but one song that is shorter than 3 minutes (song 1), we observed a statistically significant increase in Standard Deviation of the RR intervals (SDRR) (song 1: P=.125, r=.333; song 2: P=.023, r=.575; song 3: P=.014, r=.635; song 4: P=.014, r=.635) and in the Low Frequency (LF) component of the cardiac spectrogram (song 1: P=.300, r=.151; song 2: P=.038, r=.514; song 3: P=.014, r=.635; song 4: P=.014, r=.635) with a large effect size r, indicating increased HRV. No significant change in mean HR was observed (song 1: P=.173 r=-.272; song 2: P=.058, r=-.454; song 3: P=.125, r=-.333; song 4: P=.232. r=-.212). CONCLUSIONS Listening to pre-selected songs of longer duration than 3 minutes 30 seconds is associated with significant increases in HRV measures, especially SDRR and LF. Music thus has the potential to overcome autonomic nervous system (ANS) dysregulation and thereby benefit health and wellbeing.

Changes in the Cortex Neurons in Single and Fractional Gamma Radiation

2021 ◽  
Vol 66 (4) ◽  
pp. 18-24
Author(s):  
I. Ushakov ◽  
Vladimir Fyodorov
Keyword(s):  
Nervous System ◽  
Cerebral Cortex ◽  
Radiation Exposure ◽  
Comparative Assessment ◽  
Male Rats ◽  
Fractionated Irradiation ◽  
Radiation Induced ◽  
Post Radiation ◽  
Induced Changes ◽  
The Brain

Purpose: Comparative assessment of radiation-induced changes in neurons of the cerebral cortex after a single and fractionated exposure to ionizing radiation in doses of 0.1 – 1.0 Gy. Material and methods. The study was carried out in compliance with the rules of bioethics on 180 white outbred male rats at the age of 4 months. by the beginning of the experiment, exposed to a single or fractionated exposure to γ-quanta of 60Co in total doses of 0.1; 0.2; 0.5 and 1.0 Gy. Neuromorphological and histochemical methods were used to assess morphometric and tinctorial parameters of nerve cells, as well as changes in the content of protein and nucleic acids in neurons in the early and late periods of the post-radiation period. Using one-way analysis of variance, a comparative assessment of neuromorphological indicators under various modes of radiation exposure is given. Results: In the control and irradiated animals throughout their life, undulating changes in the indicators of the state of the neurons of the brain occur with a gradual decrease by the end of the experiment. Despite a number of features of the dynamics of neuromorphological parameters, these irradiation regimes do not cause functionally significant changes in the neurons of the cortex. However, in some periods of the post-radiation period, the changes under the studied irradiation regimes were multidirectional and did not always correspond to age control. Significant differences in the response of neurons to these modes of radiation exposure in the sensory and motor areas of the cerebral cortex have not been established. Conclusion: No functionally significant radiation-induced changes in neurons were found either with single or fractionated irradiation. At the same time, different modes of irradiation in general caused the same type of changes in neurons. However, in some periods of observation, changes in neuromorphological parameters under the studied irradiation regimes were not unidirectional and differed from age control, which indicates a possible risk of disturbances in the functioning of the nervous system against the background of other harmful and dangerous factors.

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